She "has embarked on a treatment program at the Priory Clinic. She wants to be ready for performances in Europe this summer and decided to seek an assessment. She will remain at the Priory on doctors' advice," the rep said in a statement.

According to a source close to the singer, it was a move initiated by her father Mitch Winehouse. "Her dad sat her down and said 'I think you're drinking too much again.' So she agreed to go an assessment to stop it becoming a bigger problem."

The singer downed a miniature bottle of Smirnoff vodka on her way to the clinic on Wednesday, "in typical Amy style," said the friend.

Fortunately the singer, who has a series of summer gigs planned in Europe kicking off June 18, took heed to her father's words and checked herself into the clinic. "She's determined, and this is all off her own back," said the source. "It's just a lapse. There are ups and downs on the road, and there have been mostly ups recently. But this is a down and she's done the right thing and gone to rehab."